Colorectal cancer is the second leading cause of cancer death in the United States and colonoscopy is the preferred screening procedure, with about 12 million procedures performed per year. Please see Peery A F, Dellon E S, Lund J, et al. Burden of gastrointestinal disease in the United States: 2012 update. Gastroenterology. November 2012; 143 (5):1179-1187. However, standard colonoscopy is far from perfect as standard forward-viewing endoscopes are unable to visualize polyps hidden by haustral folds and flexures of the colon as illustrated in FIG. 1, where (a) the forward view shows no polyps, but when the tip of the scope is sharply bent to look backwards, which is not often possible, (b) a polyp hidden behind a fold is easily seen. Well over 20% of polyps can be missed during colonoscopy and some of these lead to unexpected cancers.
Lesions are missed because they are i) hidden from forward view and ii) because they have poor color contrast. New methods of improving visualization, such as wide-angle colonoscopy, cap-assisted colonoscopy, the Aer-O-Scope, and Third Eye Retroscope (TER) have not consistently improved polyp detection and have not been clinically accepted. Please see, for example, Arber N, Grinshpon R, Pfeffer J, Maor L, Bar-Meir S, Rex D. Proof-of-concept study of the Aer-O-Scope™ omnidirectional colonoscopic viewing system in ex vivo and in vivo porcine models. Endoscopy. May 2007; 39(5):412-417; Rex D K. Third Eye Retroscope: Rationale, Efficacy, Challenges. Rev Gastroenterol Disord. Winter 2009; 9(1):1-6; Waye J D, Heigh R I, Fleischer D E, et al. A retrograde-viewing device improves detection of adenomas in the colon: a prospective efficacy evaluation (with videos). Gastrointestinal Endoscopy. March 2010; 71(3):551-556. There is an unmet need for an easy to use endoscope or endoscopic probe that can be easily incorporated into current endoscopes to improve lesion detection, prevent more cancers, and lengthen screening intervals. There is also a need for providing backward and/or sideway vision during medical procedures including laparoscopic surgery, robotic surgery arthroscopy and images of body cavities such as the paranasal sinuses.
Prior art designs for solving the above problems suffer from obstructions either by the detector optics partially obstructing the illumination or by the illumination optics partially obstructing the detector. Please see Waye J D, Heigh R I, Fleischer D E, et al. A retrograde-viewing device improves detection of adenomas in the colon: a prospective efficacy evaluation (with videos). Gastrointestinal Endoscopy. March 2010; 71(3):551-556; Wang R C C, Deen M J, Armstrong D, Fang Q Y. Development of a catadioptric endoscope objective with forward and side views. Journal of Biomedical Optics. June 2011; 16(6); Ma J, Simkulet M, Smith J. C-view omnidirectional endoscope for minimally invasive surgery/diagnostics. SPIE Proceedings. 2007; 6509:65090C; Ryusuke S, Takarou E, Tomio Y. Omnidirectional vision attachment for medical endoscopes. OMNIVIS08. 2008:1-14.
Dual-view objective lenses (also called “objectives”) have been studied by a few research groups. However, the reported dual-view objectives do not have built-in illumination systems. Please see Waye J D, Heigh R I, Fleischer D E, et al. A retrograde-viewing device improves detection of adenomas in the colon: a prospective efficacy evaluation (with videos). Gastrointestinal Endoscopy. March 2010; 71(3):551-556; Wang R C C, Deen M J, Armstrong D, Fang Q Y. Development of a catadioptric endoscope objective with forward and side views. Journal of Biomedical Optics. June 2011; 16(6); Ma J, Simkulet M, Smith J. C-view omnidirectional endoscope for minimally invasive surgery/diagnostics. SPIE Proceedings. 2007; 6509:65090C; Ryusuke S, Takarou E, Tomio Y. Omnidirectional vision attachment for medical endoscopes. OMNIVIS08. 2008:1-14. Instead, they rely solely on the external illumination of the standard colonoscope. Consequently, the retrograde view is partially blocked by the colonoscope itself and the forward view of the colonoscope is partially blocked by the rear view retroscope.
Some endoscope designs use two different monitors, one for the forward view and one for the rear view, requiring the physician to watch two screens at the same time, and making it difficult for the physician to register and localize images. Please see DeMarco D C, Odstrcil E, Lara L F, et al. Impact of experience with a retrograde-viewing device on adenoma detection rates and withdrawal times during colonoscopy: the Third Eye Retroscope study group. Gastrointestinal endoscopy. March 2010; 71(3):542-550.
Dual-view imaging probes are also useful for detecting lesions or other structures not visible with forward-viewing-only instruments in other parts of the human body such as sinuses, the duodenenum, the alimentary tract, the thorax, in robotic surgery, and in natural orifice transluminal endoscopic surgery (NOTES). When a forward viewing instrument is used to inspect a portion of an alimentary tract in a tight curve, for example, the curvature of the portion may cause the instrument to slip rapidly in the tract, preventing the inner curved surface of the portion to be inspected when only the forward view is available.
Endoscopes are used for non-biological applications to visually inspect structures through a small opening, in which case these devices are known as borescopes. Structures and spaces are commonly inspected using fiber or video scopes, through a small or limited opening without dismantling an apparatus or machinery. Visual inspection is often the first mode of non-destructive testing, it is commonly used in a range of industries, including: aerospace, automobile, manufacturing, power-generation, oil and gas, transportation, electronics and computer hardware.
Borescopes are used to inspect aircraft and automobile engines quickly without the time consuming process of taking apart the complex machinery. Similarly, areas of piping and compartments in power stations that cannot be easily entered can be visually inspected using borescopes. Manufacturing processes frequently need remote visual inspection, as well as for the maintenance of complex machinery and the monitoring of processes in a clean environment.
Borescopes are generally forward viewing, or have limited ability to deflect the tip to look sideways or partly backwards. The tips of flexible borescopes can be deflected to allow inspections to the sides or at a different angle from the forward view. Some borescopes have interchangeable heads that enable alternate views, such as to the sides or at an angle backwards. The need to use interchangeable tips leads to lengthening of the inspection process and the components require repairs or need to be replaced. Current borescopes, with or without interchangeable heads, do not have the capability to simultaneously illuminate and provide a combined forward and backward/side view.
It is therefore desirable to provide a dual-view imaging probe that can overcome the above difficulties.